1. Field of the Invention
The present invention relates to an electronic equipment assembly for housing an electronic circuitry unit, in particular, to an electronic equipment housing of tiered type where a plurality of housings are tiered and which has common ducts for heat radiating and cabling.
2. Description of the Related Art
In electronic equipment such as telephone exchanges, a so-called push-phone main unit of building block type where the same type units can be tiered for expansion according to an increase of the line capacity has been used. When transformers and electronic components mounted in the electronic equipment housings generate heat and thereby the temperature in the housings rises, the performance of the electronic equipment is adversely affected. To solve this problem, conventionally a large number of slit-shaped air intake openings and air exhaust openings are disposed on limited regions of the side walls of the housing. Fresh air is obtained to the inside of the housing through the air intake openings, thereby cooling the electronic equipment. The heated air is expelled to the outside through the air exhaust openings. However, in the electronic equipment housings which are tiered, the heated air which was expelled from a lower electronic equipment housing heats the bottom plate of the upper electronic equipment housing. Thus, since all the electronic equipment being tiered cannot be satisfactorily cooled, the electronic circuit units are thermally affected. Consequently, the reliability and safety of the equipment are deteriorated.
In addition, since the electronic equipment housings being tiered are electrically connected each other, terminals thereof should be connected with cables to each other. These cables are normally routed on the outside of the equipment. These cables diminish the appearance of the equipment. Moreover, when the electronic equipment housing is installed, these cables are sometimes scratched and damaged or disconnected from the connectors.
Therefore, an object of the present invention is to provide an electronic equipment assembly of tiered type having common vertical ducts for each of electronic equipment housings, wherein the common vertical ducts can be used for air passageways for heat radiating and cabling ducts.